Field of the Invention
The present invention relates to a method and system for controlling a fuel cell vehicle, and more particularly, to a method and system that improve fuel efficiency by setting different conditions for activation and deactivation of an idling-stop mode based on a driving pattern.
Description of the Related Art
A fuel cell is a power generating device that converts chemical energy of fuel into electric energy by an electrochemical reaction in a fuel cell stack rather than converting chemical energy into heat through combustion. The energy is used as a power supply device for electronic devices as well as a device to supply electric power to drive vehicles or industrial or household equipment.
When a fuel cell serving as a power supply device for a vehicle is combined with an engine that is typically used in an existing vehicle, it forms a fuel cell hybrid system for a vehicle. The fuel cell hybrid system includes: a fuel cell stack configured to generate electric energy through an electrochemical reaction of a reaction gas; a hydrogen supply device configured to supply the fuel cell stack with hydrogen; an air supply device configured to supply the fuel cell stack with air that contains oxygen serving as an oxidant required for an electrochemical reaction; and a heat-and-water management system configured to discharge byproducts (e.g., heat and water) of the electrochemical reaction to maintain an optimum operation temperature of the fuel cell stack.
A fuel cell hybrid system for a vehicle involves an idling-stop technology that stops a fuel cell from generating electric energy during an idling mode of a vehicle. An avoidance operation for avoiding operation of a fuel cell when a required output power is low is required to improve efficiency and durability of a fuel cell system. Therefore, various technologies to achieve such an avoidance operation have been disclosed in the related art. For example, a control method for activation and deactivation of an idling-stop mode of a fuel cell hybrid vehicle has been developed. This control method of the related art prevents a fuel cell from operating during a low efficiency period, thereby improving fuel efficiency and a system's operation efficiency.
However, this method only involves a method for controlling a vehicle that is in an idling-stop mode or a non-idling-stop mode. In other words, this method is not a technology that is capable of setting different conditions for activation or deactivation of an idling-stop mode based on the state of a vehicle. In particular, activation and deactivation of an idling-stop mode are performed based on fixed criteria, regardless of the state of the vehicle. Therefore, this control method does not reflect various variables such as a driving pattern or a state of a fuel cell when activating or deactivating an idling-stop mode.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.